A lot of the striker fired weapons will say in the manual that it's not a bad thing to dry fire them and as stated there are times when you have to. But if it was me I'd try to keep it to a minimum. It's just too inexpensive to not use the caps way I see it.

It seems I remember seeing in my Glock manual though that they said it was OK to do it. My Sigma manual said it was fine too. But I used snap caps when I practiced just the same. I can't remember the XD manual. As far as warantee things go if the manual don't say don't do it then I guess it's OK but for me I would have that lingering feeling that the pin would mess up the one time I really needed that weapon. and with the price of snap caps it just don't seem too pricey an insurance policy.